Avastin optimum dosing schedule defined

When using bevacizumab (Avastin) to treat choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD), a loading dose (LD) of bevacizumab is more effective than an as-needed (PRN) dosing schedule, according to study results published in the December issue of the British Journal of Ophthalmology.

Dr Luis Arias of the Department of Ophthalmology at the Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain and colleagues segregated patients into two groups: the LD group received bevacizumab monthly for three months followed by as-needed dosing, and the PRN group received a single injection of bevacizumab followed by as-needed dosing. Doctors considered that another injection of bevacizumab was necessary if any of the following factors were present: macular oedema (either persistent or recurrent), pigment epithelial detachment or subretinal fluid.

At six months, no ocular or systemic side effects were observed in either group. In the LD group, mean visual acuity increased by 13.7 letters, and 36% of subjects had gained 15 or more letters; mean foveal thickness decreased by 91.3 µm. In comparison, in the PRN group, mean visual acuity increased by only 4.6 letters, and just 12% of subjects had gained 15 or more letters; mean foveal thickness decreased by 48.2 µm.

Thus the researchers concluded that an LD regime was a more effective and equally safe treatment protocol when compared with PRN dosing.